Neuropsychological functioning in migraine headache, nonheadache chronic pain, and mild traumatic brain injury patients.

There are conflicting reports in the literature concerning the neuropsychological functioning of migraine headache patients. The finding in some studies that migraineurs performed more poorly than healthy controls led to the hypothesis that chronic migraine may result in subtle but persistent cerebral dysfunction. Reports describing acute and between-headache neurophysiological disturbances in migraineurs lent support to this hypothesis. To elucidate the cognitive status of these patients, we administered a brief neuropsychological battery to 60 individuals with migraine headache (HA), nonheadache chronic pain (PAIN), or mild traumatic brain injury (MTBI). The PAIN group was included to test the hypothesis that cognitive difficulty in migraineurs might result from the discomfort, depression, medications, etc. often associated with chronic pain, rather than from brain dysfunction. The MTBI patients were considered a useful comparison for the migraineurs because their level of impairment was also expected to be mild, at worst. A MANOVA, with three cognitive index scores as the dependent variables, revealed that the three groups differed significantly. Follow-up contrasts demonstrated that the MTBI group was significantly more impaired on the memory index compared to the HA and PAIN groups, which did not differ from each other. The use of two different normative-based cutoffs to identify individuals who were impaired on the test battery revealed that the frequency of impairment within the two groups of pain patients, but not the MTBI patients, was within normal limits. Thus, the results did not support a link between migraine headache and cognitive impairment.